feat(taxref): taxons comparison through path

apptax/taxonomie/models.py

@@ -230,6 +230,9 @@ def where_params(cls, filters=None, *, query):
                 query = query.filter(col.ilike(value + "%"))
         return query
 
+    def __le__(self, other):
+        return self.tree <= other.tree
+
 
 @serializable
 class BibListes(db.Model):
@@ -546,6 +549,11 @@ class TaxrefTree(db.Model):
     taxref = db.relationship(Taxref, backref=backref("tree", uselist=False))
     path = db.Column(db.String, nullable=False)
 
+    def __le__(self, other):
+        # self <= other means taxon other is the same or a parent of self
+        p1, p2 = self.path.split("."), other.path.split(".")
+        return len(p1) >= len(p2) and p1[: len(p2)] == p2
+
 
 # Taxref deffered properties